Obviously the Church must know them very well since they are popularly believed to have received divine inspiration from God Himself. Right? Actually, they don't.
For example, we will note that every Gospel begins with the introduction "According to..." such as:
"The Gospel according to Mark"
"The Gospel according to Matthew"
"The Gospel according to Luke"
"The Gospel according to John"
The obvious conclusion for the average man on the street is that these people are known to be the authors of the books attributed to them.
This, however is not the case. Why? Because not one of the vaunted 4,000 copies existent carries its author's signature.
It has just been assumed that certain people were the authors of the books.